2 files changed, 75 insertions, 6 deletions

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 4c6a72d3d48..ecd93894c80 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -604,10 +604,54 @@ static void alps_process_packet_v3(struct psmouse *psmouse)
 
 static void alps_process_packet_v4(struct psmouse *psmouse)
 {
+        struct alps_data *priv = psmouse->private;
         unsigned char *packet = psmouse->packet;
         struct input_dev *dev = psmouse->dev;
+        int offset;
         int x, y, z;
         int left, right;
+        int x1, y1, x2, y2;
+        int fingers = 0;
+        unsigned int x_bitmap, y_bitmap;
+
+        /*
+         * v4 has a 6-byte encoding for bitmap data, but this data is
+         * broken up between 3 normal packets. Use priv->multi_packet to
+         * track our position in the bitmap packet.
+         */
+        if (packet[6] & 0x40) {
+                /* sync, reset position */
+                priv->multi_packet = 0;
+        }
+
+        if (WARN_ON_ONCE(priv->multi_packet > 2))
+                return;
+
+        offset = 2 * priv->multi_packet;
+        priv->multi_data[offset] = packet[6];
+        priv->multi_data[offset + 1] = packet[7];
+
+        if (++priv->multi_packet > 2) {
+                priv->multi_packet = 0;
+
+                x_bitmap = ((priv->multi_data[2] & 0x1f) << 10) |
+                           ((priv->multi_data[3] & 0x60) << 3) |
+                           ((priv->multi_data[0] & 0x3f) << 2) |
+                           ((priv->multi_data[1] & 0x60) >> 5);
+                y_bitmap = ((priv->multi_data[5] & 0x01) << 10) |
+                           ((priv->multi_data[3] & 0x1f) << 5) |
+                            (priv->multi_data[1] & 0x1f);
+
+                fingers = alps_process_bitmap(x_bitmap, y_bitmap,
+                                              &x1, &y1, &x2, &y2);
+
+                /* Store MT data.*/
+                priv->fingers = fingers;
+                priv->x1 = x1;
+                priv->x2 = x2;
+                priv->y1 = y1;
+                priv->y2 = y2;
+        }
 
         left = packet[4] & 0x01;
         right = packet[4] & 0x02;
@@ -617,21 +661,44 @@ static void alps_process_packet_v4(struct psmouse *psmouse)
         y = ((packet[2] & 0x7f) << 4) | (packet[3] & 0x0f);
         z = packet[5] & 0x7f;
 
+        /*
+         * If there were no contacts in the bitmap, use ST
+         * points in MT reports.
+         * If there were two contacts or more, report MT data.
+         */
+        if (priv->fingers < 2) {
+                x1 = x;
+                y1 = y;
+                fingers = z > 0 ? 1 : 0;
+        } else {
+                fingers = priv->fingers;
+                x1 = priv->x1;
+                x2 = priv->x2;
+                y1 = priv->y1;
+                y2 = priv->y2;
+        }
+
         if (z >= 64)
                 input_report_key(dev, BTN_TOUCH, 1);
         else
                 input_report_key(dev, BTN_TOUCH, 0);
 
+        alps_report_semi_mt_data(dev, fingers, x1, y1, x2, y2);
+
+        input_report_key(dev, BTN_TOOL_FINGER, fingers == 1);
+        input_report_key(dev, BTN_TOOL_DOUBLETAP, fingers == 2);
+        input_report_key(dev, BTN_TOOL_TRIPLETAP, fingers == 3);
+        input_report_key(dev, BTN_TOOL_QUADTAP, fingers == 4);
+
+        input_report_key(dev, BTN_LEFT, left);
+        input_report_key(dev, BTN_RIGHT, right);
+
         if (z > 0) {
                 input_report_abs(dev, ABS_X, x);
                 input_report_abs(dev, ABS_Y, y);
         }
         input_report_abs(dev, ABS_PRESSURE, z);
 
-        input_report_key(dev, BTN_TOOL_FINGER, z > 0);
-        input_report_key(dev, BTN_LEFT, left);
-        input_report_key(dev, BTN_RIGHT, right);
-
         input_sync(dev);
 }
 
@@ -1557,6 +1624,7 @@ int alps_init(struct psmouse *psmouse)
                 input_set_abs_params(dev1, ABS_Y, 0, 767, 0, 0);
                 break;
         case ALPS_PROTO_V3:
+        case ALPS_PROTO_V4:
                 set_bit(INPUT_PROP_SEMI_MT, dev1->propbit);
                 input_mt_init_slots(dev1, 2);
                 input_set_abs_params(dev1, ABS_MT_POSITION_X, 0, ALPS_V3_X_MAX, 0, 0);
@@ -1565,8 +1633,7 @@ int alps_init(struct psmouse *psmouse)
                 set_bit(BTN_TOOL_DOUBLETAP, dev1->keybit);
                 set_bit(BTN_TOOL_TRIPLETAP, dev1->keybit);
                 set_bit(BTN_TOOL_QUADTAP, dev1->keybit);
-                /* fall through */
-        case ALPS_PROTO_V4:
+
                 input_set_abs_params(dev1, ABS_X, 0, ALPS_V3_X_MAX, 0, 0);
                 input_set_abs_params(dev1, ABS_Y, 0, ALPS_V3_Y_MAX, 0, 0);
                 break;
diff --git a/drivers/input/mouse/alps.h b/drivers/input/mouse/alps.h
index a00a4ab92a0..ae1ac354c77 100644
--- a/drivers/input/mouse/alps.h
+++ b/drivers/input/mouse/alps.h
@@ -39,6 +39,8 @@ struct alps_data {
         int prev_fin;                   /* Finger bit from previous packet */
         int multi_packet;               /* Multi-packet data in progress */
         unsigned char multi_data[6];    /* Saved multi-packet data */
+        int x1, x2, y1, y2;             /* Coordinates from last MT report */
+        int fingers;                    /* Number of fingers from MT report */
         u8 quirks;
         struct timer_list timer;
 };